Multi-stage process and device for treatment heavy marine fuel oil and resultant composition including ultrasound promoted desulfurization

ABSTRACT

A multi-stage process for reducing the environmental contaminants in an ISO8217 compliant Feedstock Heavy Marine Fuel Oil involving a core desulfurizing process and a ultrasound treatment process as either a pre-treating step or post-treating step to the core process. The Product Heavy Marine Fuel Oil complies with ISO 8217 for residual marine fuel oils and has a sulfur level has a maximum sulfur content (ISO 14596 or ISO 8754) between the range of 0.05 mass % to 1.0 mass. A process plant for conducting the process is also disclosed.

BACKGROUND

There are two basic marine fuel types: distillate based marine fuel,also known as Marine Gas Oil (MGO) or Marine Diesel Oil (MDO); andresidual based marine fuel, also known as heavy marine fuel oil (HMFO).Distillate based marine fuel both MGO and MDO, comprises petroleummiddle distillate fractions separated from crude oil in a refinery via adistillation process. Gasoil (also known as medium diesel) is apetroleum middle distillate in boiling range and viscosity betweenkerosene (light distillate) and lubricating oil (heavy distillate)containing a mixture of C10 to C19 hydrocarbons. Gasoil (a heavydistillate) is used to heat homes and is used blending with lightermiddle distillates as a fuel for heavy equipment such as cranes,bulldozers, generators, bobcats, tractors and combine harvesters.Generally maximizing middle distillate recovery from heavy distillatesmixed with petroleum residues is the most economic use of thesematerials by refiners because they can crack gas oils into valuablegasoline and distillates in a fluid catalytic cracking (FCC) unit.Diesel oils for road use are very similar to gas oils with road usediesel containing predominantly contain a middle distillate mixture ofC10 through C19 hydrocarbons, which include approximately 64% aliphatichydrocarbons, 1-2% olefinic hydrocarbons, and 35% aromatic hydrocarbons.Distillate based marine fuels (MDO and MGO) are essentially road dieselor gas oil fractions blended with up to 15% residual process streams,and optionally up to 5% volume of polycyclic aromatic hydrocarbons(asphaltenes). The residual and asphaltene materials are blended intothe middle distillate to form MDO and MGO as a way to both swell volumeand productively use these low value materials.

Asphaltenes are large and complex polycyclic hydrocarbons with apropensity to form complex and waxy precipitates, especially in thepresence of aliphatic (paraffinic) hydrocarbons that are the primarycomponent of Marine Diesel. Once asphaltenes have precipitated out, theyare notoriously difficult to re-dissolve and are described as fuel tanksludge in the marine shipping industry and marine bunker fuelingindustry. One of skill in the art will appreciate that mixing MarineDiesel with asphaltenes and process residues is limited by thecompatibility of the materials and formation of asphaltene precipitatesand the minimum Cetane number required for such fuels.

Residual based fuels or Heavy Marine Fuel Oil (HMFO) are used by largeocean-going ships as fuel for large two stroke diesel engines for over50 years. HMFO is a blend of the residues generated throughout the crudeoil refinery process. Typical refinery streams combined to from HMFO mayinclude, but are not limited to: atmospheric tower bottoms (i.e.atmospheric residues), vacuum tower bottoms (i.e. vacuum residues)visbreaker residue, FCC Light Cycle Oil (LCO), FCC Heavy Cycle Oil (HCO)also known as FCC bottoms, FCC Slurry Oil, heavy gas oils and delayedcracker oil (DCO), deasphalted oils (DAO); heavy aromatic residues andmixtures of polycylic aromatic hydrocarbons, reclaimed land transportmotor oils; pyrolysis oils and tars; aspahltene solids and tars; andminor portions (often less than 20% vol.) of middle distillate materialssuch as cutter oil, kerosene or diesel to achieve a desired viscosity.HMFO has a higher aromatic content (especially polynuclear aromatics andasphaltenes) than the marine distillate fuels noted above. The HMFOcomponent mixture varies widely depending upon the crude slate (i.e.source of crude oil) processed by a refinery and the processes utilizedwithin that refinery to extract the most value out of a barrel of crudeoil. The HMFO is generally characterized as being highly viscous, highin sulfur and metal content (up to 5 wt %), and high in asphaltenesmaking HMFO the one product of the refining process that hashistorically had a per barrel value less than feedstock crude oil.

Industry statistics indicate that about 90% of the HMFO sold contains3.5 weight % sulfur. With an estimated total worldwide consumption ofHMFO of approximately 300 million tons per year, the annual productionof sulfur dioxide by the shipping industry is estimated to be over 21million tons per year. Emissions from HMFO burning in ships contributesignificantly to both global marine air pollution and local marine airpollution levels.

The International Convention for the Prevention of Pollution from Ships,also known as the MARPOL convention or just MARPOL, as administered bythe International Maritime Organization (IMO) was enacted to preventmarine pollution (i.e. marpol) from ships. In 1997, a new annex wasadded to the MARPOL convention; the Regulations for the Prevention ofAir Pollution from Ships—Annex VI to minimize airborne emissions fromships (SO_(x), NO_(x), ODS, VOC) and their contribution to global airpollution. A revised Annex VI with tightened emissions limits wasadopted in October 2008 and effective 1 Jul. 2010 (hereafter calledAnnex VI (revised) or simply Annex VI).

MARPOL Annex VI (revised) adopted in 2008 established a set of stringentair emissions limits for all vessel and designated Emission ControlAreas (ECAs). The ECAs under MARPOL Annex VI are: i) Baltic Sea area—asdefined in Annex I of MARPOL—SO_(x) only; ii) North Sea area—as definedin Annex V of MARPOL—SO_(x) only; iii) North American—as defined inAppendix VII of Annex VI of MARPOL—SO_(x), NO_(x) and PM; and, iv)United States Caribbean Sea area—as defined in Appendix VII of Annex VIof MARPOL—SO_(x), NO_(x) and PM.

Annex VI (revised) was codified in the United States by the Act toPrevent Pollution from Ships (APPS). Under the authority of APPS, theU.S. Environmental Protection Agency (the EPA), in consultation with theUnited States Coast Guard (USCG), promulgated regulations whichincorporate by reference the full text of Annex VI. See 40 C.F.R. §1043.100(a)(1). On Aug. 1, 2012 the maximum sulfur content of all marinefuel oils used onboard ships operating in US waters/ECA was reduced from3.5% wt. to 1.00% wt. (10,000 ppm) and on Jan. 1, 2015 the maximumsulfur content of all marine fuel oils used in the North American ECAwas lowered to 0.10% wt. (1,000 ppm). At the time of implementation, theUnited States government indicated that vessel operators must vigorouslyprepare to comply with the 0.10% wt. (1,000 ppm) US ECA marine fuel oilsulfur standard. To encourage compliance, the EPA and USCG refused toconsider the cost of compliant low sulfur fuel oil to be a valid basisfor claiming that compliant fuel oil was not available for purchase. Forover five years there has been a very strong economic incentive to meetthe marine industry demands for low sulfur HMFO, however technicallyviable solutions have not been realized and a premium price has beencommanded by refiners to supply a low sulfur HMFO compliant with AnnexVI sulfur emissions requirements in the ECA areas.

Since enactment in 2010, the global sulfur cap for HMFO outside of theECA areas was set by Annex VI at 3.50% wt. effective 1 Jan. 2012; with afurther reduction to 0.50% wt, effective 1 Jan. 2020. The global cap onsulfur content in HMFO has been the subject of much discussion in boththe marine shipping and marine fuel bunkering industry. There has beenand continues to be a very strong economic incentive to meet theinternational marine industry demands for low sulfur HMFO (i.e. HMFOwith a sulfur content less than 0.50 wt. %. Notwithstanding this globaldemand, solutions for transforming high sulfur HMFO into low sulfur HMFOhave not been realized or brought to market. There is an on-going andurgent demand for processes and methods for making a low sulfur HMFOcompliant with MARPOL Annex VI emissions requirements.

Replacement of Heavy Marine Fuel Oil with Marine Gas Oil or MarineDiesel:

One primary solution to the demand for low sulfur HMFO to simply replacehigh sulfur HMFO with marine gas oil (MGO) or marine diesel (MDO). Thefirst major difficulty is the constraint in global supply of middledistillate materials that make up 85-90% vol of MGO and MDO. It isreported that the effective spare capacity to produce MGO is less than100 million metric tons per year resulting in an annual shortfall inmarine fuel of over 200 million metric tons per year. Refiners not onlylack the capacity to increase the production of MGO, but they have noeconomic motivation because higher value and higher margins can beobtained from using middle distillate fractions for low sulfur dieselfuel for land-based transportation systems (i.e. trucks, trains, masstransit systems, heavy construction equipment, etc.).

Blending:

Another primary solution is the blending of high sulfur HMFO with lowersulfur containing fuels such as MGO or MDO low sulfur marine diesel(0.1% wt. sulfur) to achieve a Product HMFO with a sulfur content of0.5% wt. In a straight blending approach (based on linear blending)every 1 ton of high sulfur HSFO (3.5% sulfur) requires 7.5 tons of MGOor MDO material with 0.1% wt. S to achieve a sulfur level of 0.5% wt.HMFO. One of skill in the art of fuel blending will immediatelyunderstand that blending hurts key properties of the HMFO, specificallylubricity, fuel density, CCAI, viscosity, flash point and otherimportant physical bulk properties. Blending a mostly paraffinic-typedistillate fuel (MGO or MDO) with a HMFO having a high poly aromaticcontent often correlates with poor solubility of asphaltenes. A blendedfuel is likely to result in the precipitation of asphaltenes and/orwaxing out of highly paraffinic materials from the distillate materialforming an intractable fuel tank sludge. Fuel tank sludge causesclogging of filters and separators, transfer pumps and lines, build-upof sludge in storage tanks, sticking of fuel injection pumps, andplugged fuel nozzles. Such a risk to the primary propulsion system isnot acceptable for a ship in the open ocean.

It should further be noted that blending of HMFO with marine distillateproducts (MGO or MDO) is not economically viable. A blender will betaking a high value product (0.1% S marine gas oil (MGO) or marinediesel (MDO)) and blending it 7.5 to 1 with a low value high sulfur HMFOto create a final IMO/MARPOL compliant HMFO (i.e. 0.5% wt. S Low SulfurHeavy Marine Fuel Oil—LSHMFO) which will sell at a discount to the valueof the principle ingredient (i.e. MGO or MDO).

Processing of Residual Oils.

For the past several decades, the focus of refining industry researchefforts related to the processing of heavy oils (crude oils, distressedoils, or residual oils) has been on upgrading the properties of theselow value refinery process oils to create middle distillate and lighteroils with greater value. The challenge has been that crude oil,distressed oil and residues contain high levels of sulfur, nitrogen,phosphorous, metals (especially vanadium and nickel); asphaltenes andexhibit a propensity to form carbon or coke on the catalyst. The sulfurand nitrogen molecules are highly refractory and aromatically stable anddifficult and expensive to crack or remove. Vanadium and nickelporphyrins and other metal organic compounds are responsible forcatalyst contamination and corrosion problems in the refinery. Thesulfur, nitrogen, and phosphorous, must be removed because they arewell-known poisons for the precious metal (platinum and palladium)catalysts utilized in the processes downstream of the atmospheric orvacuum distillation towers.

The difficulties treating atmospheric or vacuum residual streams hasbeen known for many years and has been the subject of considerableresearch and investigation. Numerous residue-oil conversion processeshave been developed in which the goals are same: 1) create a morevaluable, preferably middle distillate range hydrocarbons; and 2)concentrate the contaminates such as sulfur, nitrogen, phosphorous,metals and asphaltenes into a form (coke, heavy coker residue, FCCslurry oil) for removal from the refinery stream. Well known andaccepted practice in the refining industry is to increase the reactionseverity (elevated temperature and pressure) to produce hydrocarbonproducts that are lighter and more purified, increase catalyst lifetimes and remove sulfur, nitrogen, phosphorous, metals and asphaltenesfrom the refinery stream.

In summary, since the announcement of the MARPOL Annex VI standardsreducing the global levels of sulfur in HMFO, refiners of crude oil havehad modest success in their technical efforts to create a process forthe production of a low sulfur substitute for high sulfur HMFO. Despitethe strong governmental and economic incentives and needs of theinternational marine shipping industry, refiners have little economicreason to address the removal of environmental contaminates from highsulfur HMFOs. The global refining industry has been focused upongenerating greater value from each barrel of oil by creating middledistillate hydrocarbons (i.e. diesel) and concentrating theenvironmental contaminates into increasingly lower value streams (i.e.residues) and products (petroleum coke, HMFO). Shipping companies havefocused on short term solutions, such as the installation of scrubbingunits, or adopting the limited use of more expensive low sulfur marinediesel and marine gas oils as a substitute for HMFO. On the open seas,most if not all major shipping companies continue to utilize the mosteconomically viable fuel, that is HMFO. There remains a long standingand unmet need for processes and devices that remove the environmentalcontaminants (i.e. sulfur, nitrogen, phosphorous, metals especiallyvanadium and nickel) from HMFO without altering the qualities andproperties that make HMFO the most economic and practical means ofpowering ocean going vessels.

SUMMARY

It is a general objective to reduce the environmental contaminates froma Heavy Marine Fuel Oil (HMFO) in a multi stage process including theuse of ultrasonic desulfurization, that minimizes the changes in thedesirable properties of the HMFO and minimizes the unnecessaryproduction of by-product hydrocarbons (i.e. light hydrocarbons havingC₁-C₄ and wild naptha (C₅-C₂₀)).

A first aspect and illustrative embodiment encompasses a multi-stageprocess for reducing the environmental contaminants in a Feedstock HeavyMarine Fuel Oil, the process involving: contacting a Feedstock HeavyMarine Fuel Oil with a ultrasonic desulfurization process to give apre-treated Feedstock Heavy Marine Fuel Oil; mixing a quantity of thepre-treated Feedstock Heavy Marine Fuel Oil with a quantity ofActivating Gas mixture to give a Feedstock Mixture; contacting theFeedstock Mixture with one or more catalysts under desulfurizingconditions to form a Process Mixture from the Feedstock Mixture;receiving the Process Mixture and separating the Product Heavy MarineFuel Oil liquid components of the Process Mixture from the gaseouscomponents and by-product hydrocarbon components of the Process Mixtureand, discharging the Product Heavy Marine Fuel Oil.

A second aspect and illustrative embodiment encompasses a process forreducing the environmental contaminants in HMFO, in which the processinvolves: mixing a quantity of Feedstock Heavy Marine Fuel Oil with aquantity of Activating Gas mixture to give a Feedstock Mixture;contacting the Feedstock Mixture with one or more catalysts underdesulfurizing conditions to form a Process Mixture from the FeedstockMixture; receiving the Process Mixture and separating the liquidcomponents of the Process Mixture from the bulk gaseous components ofthe Process Mixture; receiving the liquid components and contacting theliquid components with a ultrasonic desulfurization process; thenseparating any residual gaseous components and by-product hydrocarboncomponents from the Product Heavy Marine Fuel Oil; and, discharging theProduct Heavy Marine Fuel Oil.

A third and fourth aspect and illustrative embodiment encompasses adevice for reducing environmental contaminants in a Feedstock HMFO andproducing a Product HMFO. The illustrative devices embody the aboveillustrative processes on a commercial scale.

A fifth aspect and illustrative embodiment encompasses a Heavy MarineFuel Oil composition resulting from the above illustrative processes.

DESCRIPTION OF DRAWINGS

FIG. 1 is a process block flow diagram of an illustrative core processto produce Product HMFO.

FIG. 2 is a process flow diagram of a multistage process utilizing anultrasonic desulfurization process to pre-treat the feedstock HMFO and asubsequent core process to produce Product HMFO.

FIG. 3 is a process flow diagram of a multi-stage process utilizing acore process followed by a subsequent ultrasonic desulfurization processto produce Product HMFO.

FIG. 4 is a basic schematic diagram of a plant to produce Product HMFOutilizing a combination of an ultrasonic desulfurization process topre-treat the feedstock HMFO and a subsequent core process to produceProduct HMFO.

FIG. 5 is a basic schematic diagram of a plant to produce Product HMFOutilizing a combination of a core process and ultrasonic desulfurizationprocess to produce Product HMFO.

DETAILED DESCRIPTION

The inventive concepts as described herein utilize terms that should bewell known to one of skill in the art, however certain terms areutilized having a specific intended meaning and these terms are definedbelow:

Heavy Marine Fuel Oil (HMFO) is a petroleum product fuel compliant withthe ISO 8217 (2017) standards for the bulk properties of residual marinefuels except for the concentration levels of the EnvironmentalContaminates.

Environmental Contaminates are organic and inorganic components of HMFOthat result in the formation of SO_(x), NO_(x) and particulate materialsupon combustion.

Feedstock HMFO is a petroleum product fuel compliant with the ISO 8217(2017) standards for the bulk properties of residual marine fuels exceptfor the concentration of Environmental Contaminates, preferably theFeedstock HMFO has a sulfur content greater than the global MARPOLstandard of 0.5% wt. sulfur, and preferably and has a sulfur content(ISO 14596 or ISO 8754) between the range of 5.0% wt. to 1.0% wt.

Product HMFO is a petroleum product fuel compliant with the ISO 8217(2017) standards for the bulk properties of residual marine fuels andachieves a sulfur content lower than the global MARPOL standard of 0.5%wt. sulfur (ISO 14596 or ISO 8754), and preferably a maximum sulfurcontent (ISO 14596 or ISO 8754) between the range of 0.05% wt. to 1.0%wt.

Activating Gas: is a mixture of gases utilized in the process combinedwith the catalyst to remove the environmental contaminates from theFeedstock HMFO.

Fluid communication: is the capability to transfer fluids (eitherliquid, gas or combinations thereof, which might have suspended solids)from a first vessel or location to a second vessel or location, this mayencompass connections made by pipes (also called a line), spools,valves, intermediate holding tanks or surge tanks (also called a drum).

Merchantable quality: is a level of quality for a residual marine fueloil so the fuel is fit for the ordinary purpose it should serve (i.e.serve as a residual fuel source for a marine ship) and can becommercially sold as and is fungible with heavy or residual marinebunker fuel.

Bbl or bbl: is a standard volumetric measure for oil; 1 bbl=0.1589873m³; or 1 bbl=158.9873 liters; or 1 bbl=42.00 US liquid gallons.

Bpd: is an abbreviation for Bbl per day.

SCF: is an abbreviation for standard cubic foot of a gas; a standardcubic foot (at 14.73 psi and 60° F.) equals 0.0283058557 standard cubicmeters (at 101.325 kPa and 15° C.).

The inventive concepts are illustrated in more detail in thisdescription referring to the drawings, in which FIG. 1 shows thegeneralized block process flows for a core process of reducing theenvironmental contaminates in a Feedstock HMFO and producing a ProductHMFO. A predetermined volume of Feedstock HMFO (2) is mixed with apredetermined quantity of Activating Gas (4) to give a FeedstockMixture. The Feedstock HMFO utilized generally complies with the bulkphysical and certain key chemical properties for a residual marine fueloil otherwise compliant with ISO 8217 (2017) exclusive of theEnvironmental Contaminates. More particularly, when the EnvironmentalContaminate is sulfur, the concentration of sulfur in the Feedstock HMFOmay be between the range of 5.0% wt. to 1.0% wt. The Feedstock HMFOshould have bulk physical properties required of an ISO 8217 (2017)compliant HMFO of: a maximum of kinematic viscosity at 50 C (ISO 3104)between the range from 180 mm²/s to 700 mm²/s; a maximum of density at15° C. (ISO 3675) between the range of 991.0 kg/m³ to 1010.0 kg/m³; aCCAI is in the range of 780 to 870; a flash point (ISO 2719) no lowerthan 60° C.; a total sediment-aged (ISO 10307-2) less than 0.10 mass %;and a carbon residue-micro method (ISO 10370) less than 20.00 mass % andpreferably also a aluminum plus silicon (ISO 10478) content less than 60mg/kg. Environmental Contaminates other than sulfur that may be presentin the Feedstock HMFO over the ISO requirements may include vanadium,nickel, iron, aluminum and silicon substantially reduced by the processof the present invention. However, one of skill in the art willappreciate that the vanadium content serves as a general indicator ofthese other Environmental Contaminates. In one preferred embodiment thevanadium content is ISO compliant so the Feedstock MHFO has a maximumvanadium content (ISO 14597) between the range from 350 mg/kg to 450 ppmmg/kg.

As for the properties of the Activating Gas, the Activating Gas shouldbe selected from mixtures of nitrogen, hydrogen, carbon dioxide, gaseouswater, and methane. The mixture of gases within the Activating Gasshould have an ideal gas partial pressure of hydrogen (p_(H2)) greaterthan 80% of the total pressure of the Activating Gas mixture (P) andmore preferably wherein the Activating Gas has an ideal gas partialpressure of hydrogen (p_(H2)) greater than 90% of the total pressure ofthe Activating Gas mixture (P). It will be appreciated by one of skillin the art that the molar content of the Activating Gas is anothercriterion the Activating Gas should have a hydrogen mole fraction in therange between 80% and 100% of the total moles of Activating Gas mixture.

The Feedstock Mixture (i.e. mixture of Feedstock HMFO and ActivatingGas) is brought up to the process conditions of temperature and pressureand introduced into a first vessel, preferably a reactor vessel, so theFeedstock Mixture is then contacted with one or more catalysts (8) toform a Process Mixture from the Feedstock Mixture.

The core process reactive conditions are selected so the ratio of thequantity of the Activating Gas to the quantity of Feedstock HMFO is 250scf gas/bbl of Feedstock HMFO to 10,000 scf gas/bbl of Feedstock HMFO;and preferably between 2000 scf gas/bbl of Feedstock HMFO 1 to 5000 scfgas/bbl of Feedstock HMFO more preferably between 2500 scf gas/bbl ofFeedstock HMFO to 4500 scf gas/bbl of Feedstock HMFO. The processconditions are selected so the total pressure in the first vessel isbetween of 250 psig and 3000 psig; preferably between 1000 psig and 2500psig, and more preferably between 1500 psig and 2200 psig. The processconditions are selected so the indicated temperature within the firstvessel is between of 500° F. to 900° F., preferably between 650° F. and850° F. and more preferably between 680° F. and 800° F. The processconditions are selected so the liquid hourly space velocity within thefirst vessel is between 0.05 oil/hour/m³ catalyst and 1.0 oil/hour/m³catalyst; preferably between 0.08 oil/hour/m³ catalyst and 0.5oil/hour/m³ catalyst; and more preferably between 0.1 oil/hour/m³catalyst and 0.3 oil/hour/m³ catalyst to achieve deep desulfurizationwith product sulfur levels below 0.1 ppmw.

One of skill in the art will appreciate that the core process reactiveconditions are determined to consider the hydraulic capacity of theunit. Exemplary hydraulic capacity for the treatment unit may be between100 bbl of Feedstock HMFO/day and 100,000 bbl of Feedstock HMFO/day,preferably between 1000 bbl of Feedstock HMFO/day and 60,000 bbl ofFeedstock HMFO/day, more preferably between 5,000 bbl of FeedstockHMFO/day and 45,000 bbl of Feedstock HMFO/day, and even more preferablybetween 10,000 bbl of Feedstock HMFO/day and 30,000 bbl of FeedstockHMFO/day.

The core process may utilize one or more catalyst materials selectedfrom the group consisting of: an ebulliated bed supported transitionmetal heterogeneous catalyst, a fixed bed supported transition metalheterogeneous catalyst, and a combination of ebulliated bed supportedtransition metal heterogeneous catalysts and fixed bed supportedtransition metal heterogeneous catalysts. One of skill in the art willappreciate that a fixed bed supported transition metal heterogeneouscatalyst will be the technically easiest to implement and is preferred.The transition metal heterogeneous catalyst comprises a porous inorganicoxide catalyst carrier and a transition metal catalyst. The porousinorganic oxide catalyst carrier is at least one carrier selected fromthe group consisting of alumina, alumina/boria carrier, a carriercontaining metal-containing aluminosilicate, alumina/phosphorus carrier,alumina/alkaline earth metal compound carrier, alumina/titania carrierand alumina/zirconia carrier. The transition metal component of thecatalyst is one or more metals selected from the group consisting ofgroup 6, 8, 9 and 10 of the Periodic Table. In a preferred andillustrative embodiment, the transition metal heterogeneous catalyst isa porous inorganic oxide catalyst carrier and a transition metalcatalyst, in which the preferred porous inorganic oxide catalyst carrieris alumina and the preferred transition metal catalyst is Ni—Mo, Co—Mo,Ni—W or Ni—Co—Mo.

The Process Mixture (10) in this core process is removed from the firstvessel (8) and from being in contact with the one or more catalyst andis sent via fluid communication to a second vessel (12), preferably agas-liquid separator or hot separators and cold separators, forseparating the liquid components (14) of the Process Mixture from thebulk gaseous components (16) of the Process Mixture. The gaseouscomponents (16) are treated beyond the battery limits of the immediateprocess. Such gaseous components may include a mixture of Activating Gascomponents and lighter hydrocarbons (mostly methane, ethane and propanebut some wild naphtha) that may have been formed as part of theby-product hydrocarbons from the process.

The Liquid Components (16) in this core process are sent via fluidcommunication to a third vessel (18), preferably a fuel oil productstripper system, for separating any residual gaseous components (20) andby-product hydrocarbon components (22) from the Product HMFO (24). Theresidual gaseous components (20) may be a mixture of gases selected fromthe group consisting of: nitrogen, hydrogen, carbon dioxide, hydrogensulfide, gaseous water, C₁-C₅ hydrocarbons. This residual gas is treatedoutside of the battery limits of the immediate process, combined withother gaseous components (16) removed from the Process Mixture (10) inthe second vessel (12). The liquid by-product hydrocarbon component,which are condensable hydrocarbons formed in the process (22) may be amixture selected from the group consisting of C₅-C₂₀ hydrocarbons (wildnaphtha) (naphtha-diesel) and other condensable light liquid (C₃-C₈)hydrocarbons that can be utilized as part of the motor fuel blendingpool or sold as gasoline and diesel blending components on the openmarket. These liquid by-product hydrocarbons should be less than 15%wt., preferably less than 5% wt. and more preferably less than 3% wt. ofthe overall process mass balance.

The Product HMFO (24) resulting from the core process is discharged viafluid communication into storage tanks beyond the battery limits of theimmediate process. The Product HMFO complies with ISO 8217 (2017) andhas a maximum sulfur content (ISO 14596 or ISO 8754) between the rangeof 0.05 mass % to 1.0 mass % preferably a sulfur content (ISO 14596 orISO 8754) between the range of 0.05 mass % ppm and 0.7 mass % and morepreferably a sulfur content (ISO 14596 or ISO 8754) between the range of0.1 mass % and 0.5 mass %. The vanadium content of the Product HMFO isalso ISO compliant with a maximum vanadium content (ISO 14597) betweenthe range from 350 mg/kg to 450 ppm mg/kg, preferably a vanadium content(ISO 14597) between the range of 200 mg/kg and 300 mg/kg and morepreferably a vanadium content (ISO 14597) less than 50 mg/kg.

The Product HFMO should have bulk physical properties of: a kinematicviscosity at 50° C. (ISO 3104) between the range from 180 mm²/s to 700mm²/s; a density at 15° C. (ISO 3675) between the range of 991.0 kg/m³to 1010.0 kg/m³; a CCAI is in the range of 780 to 870; a flash point(ISO 2719) no lower than 60° C.; a total sediment-aged (ISO 10307-2)less than 0.10 mass %; and a carbon residue-micro method (ISO 10370)less than 20.00 mass % and also preferably a maximum aluminum plussilicon (ISO 10478) content of 60 mg/kg.

The Product HMFO will have a sulfur content (ISO 14596 or ISO 8754)between 1% and 20% of the maximum sulfur content of the Feedstock HeavyMarine Fuel Oil. That is the sulfur content of the Product will bereduced by about 80% or greater when compared to the Feedstock HMFO.Similarly, the vanadium content (ISO 14597) of the Product Heavy MarineFuel Oil is between 1% and 20% of the maximum vanadium content of theFeedstock Heavy Marine Fuel Oil. One of skill in the art will appreciatethat the above data indicates a substantial reduction in sulfur andvanadium content indicate a process having achieved a substantialreduction in the Environmental Contaminates from the Feedstock HMFOwhile maintaining the desirable properties of an ISO compliant HMFO.

As a side note, the residual gaseous component is a mixture of gasesselected from the group consisting of: nitrogen, hydrogen, carbondioxide, hydrogen sulfide, gaseous water, C₁-C₅ hydrocarbons. An aminescrubber will effectively remove the hydrogen sulfide content which canthen be processed using technologies and processes well known to one ofskill in the art. In one preferable illustrative embodiment, thehydrogen sulfide is converted into elemental sulfur using the well-knownClaus process. An alternative embodiment utilizes a proprietary processfor conversion of the Hydrogen sulfide to hydrosulfuric acid. Eitherway, the sulfur is removed from entering the environment prior tocombusting the HMFO in a ships engine. The cleaned gas can be vented,flared or more preferably recycled back for use as Activating Gas.

Ultrasound Treatment Process: It will be appreciated by one of skill inthe art, that the conditions utilized in the core process have beenintentionally selected to minimize cracking of hydrocarbons and removesignificant levels of sulfur from the Feedstock HMFO. However, one ofskill in the art will also appreciate there may be certain compoundspresent in the Feedstock HMFO removal of which would have a positiveimpact upon the properties of the Product HMFO. These processes andsystems must achieve this without substantially altering the desirablebulk properties (i.e. compliance with ISO 8217 (2017) exclusive ofsulfur content) of the Product HMFO.

The ultrasound utilized in the present illustrative embodiment may be aconventional industrial high energy transducer for chemical reactionssuch as those disclosed in U.S. Pat. Nos. 6,897,628; 7,712,353;7,928,614; 7,790,002; 7,879,200; US20090038932. Alternatively a looptype ultrasound generator such as that disclosed in U.S. Pat. No.7,275,440 (the contents of which are incorporated herein by reference)may be used. When water or supercritical water is present with the HMFOthe relative amounts of the oil and aqueous phases in the emulsion mayvary usually however, best results will be achieved when the volumeratio of organic phase to aqueous phase is from about 25:1 to about 1:5,preferably from about 20:1 to about 1:2, and most preferably from about12:1 to about 1:1. A ratio presently preferred is 10:1. An optionaloxidizing agent, such as hydroperoxide or another water soluble peroxideor oxidizing agent may be present in the aqueous solution. When ahydroperoxide is present, the amount can vary. Usually best results willbe achieved with a hydroperoxide concentration of from about 10 ppm toabout 100 ppm by weight, and preferably from about 15 ppm to about 50ppm by weight, of the aqueous solution. In certain embodiments of thisinvention, a surface active agent or other emulsion stabilizer isincluded to stabilize the emulsion as the organic and aqueous phases arebeing prepared for the ultrasound exposure. A further optional componentmay be a catalytic metal. Usually water will not be present when ametallic catalyst is utilized. Examples are transition metal catalysts,preferably metals having atomic numbers of 21 through 29, 39 through 47,and 57 through 79. Particularly preferred metals from this group arenickel, silver, tungsten (and tungstates), and combinations thereof. Incertain systems within the scope of this invention, Fenton catalysts(ferrous salts) and metal ion catalysts in general such as iron (II),iron (III), copper (I), copper (II), chromium (III), chromium (VI),molybdenum, tungsten, and vanadium ions, are useful. Of these, iron(II), iron III), copper II), and tungsten catalysts are preferred. Forsome systems, Fenton-type catalysts are preferred, while for others,tungstates are preferred. Tungstates include tungstic acid, substitutedtungstic acids such as phosphotungstic acid, and metal tungstates. Themetallic catalyst when present will be used in a catalytically effectiveamount, which means any amount that will enhance the progress of thereactions by which the HMFO components are treated. The catalyst may bepresent as metal particles, pellets, screens, or any form with highsurface area and can be retained in the ultrasound chamber.

Ultrasound consists of soundlike waves at a frequency above the range ofnormal human hearing, i.e., above 20 kHz (20,000 cycles per second).Ultrasonic energy with frequencies as high as 10 gigahertz(10,000,000,000 cycles per second) has been generated, but for thisinvention, useful results will be achieved with frequencies within therange of from about 10 kHz to about 100 MHz, and preferably within therange of from about 10 kHz to about 30 MHz. Ultrasonic waves can begenerated from mechanical, electrical, electromagnetic, or thermalenergy sources. The intensity of the sonic energy may also vary widely.For this invention, best results will generally be achieved with anintensity ranging from about 30 watts/cm2 to about 300 watts/cm2, orpreferably from about 50 watts/cm2 to about 100 watts/cm2. The typicalelectromagnetic source is a magnetostrictive transducer which convertsmagnetic energy into ultrasonic energy by applying a strong alternatingmagnetic field to certain metals, alloys and ferrites. The typicalelectrical source is a piezoelectric transducer, which uses natural orsynthetic single crystals (such as quartz) or ceramics (such as bariumtitanate or lead zirconate) and applies an alternating electricalvoltage across opposite faces of the crystal or ceramic to cause analternating expansion and contraction of crystal or ceramic at theimpressed frequency. Ultrasound has wide applications in such areas ascleaning for the electronics, automotive, aircraft, and precisioninstruments industries, flow metering for closed systems such ascoolants in nuclear power plants or for blood flow in the vascularsystem, materials testing, machining, soldering and welding,electronics, agriculture, oceanography, and medical imaging. The methodsof producing and applying ultrasonic energy, and commercial suppliers ofultrasound equipment, are well known among those skilled in ultrasoundtechnology. In the preferred practice of the invention, ultrasound isadministered by used of an ultrasonic transducer and an ultrasonic horn.

The exposure time of the HMFO to ultrasound is not critical to thepractice or the success of the invention, and the optimal exposure timewill vary according to the material being treated. However, effectiveand useful results can be achieved with a relatively short exposuretime. Best results will generally be obtained with exposure timesranging from about 8 seconds to about 150 seconds.

In US20060180500, the ultrasonic treatment may be combined with amicrowave treatment, such as that disclosed in co-pending applicationentitled “Multi-Stage Process and Device for Treatment Heavy Marine FuelOil and Resultant Composition including Microwave PromotedDesulfurization” which is co-owned herewith.

The Ultrasound Treatment Unit (UTU) comprises a conventional reactorequipped with ultrasonic transducers as a source of high energyultrasound. Construction of this unit, which may operate at relativelylow pressures lower than 2 MPa, and temperatures equal to or lower than300° C., adopted in this process would not present technicaldifficulties for an experienced technician in this field. For examplesee the reactors disclosed in U.S. Pat. Nos. 4,168,295; 7,275,440 or9,339,785 as an illustrative examples of ultrasonic energy basedreactors that allow for elevated temperature, pressure, presence ofcatalytic materials, and continuous flow of feedstock materials (i.e.Feedstock HMFO and optionally hydrogen).

Generally, the ultrasonic treatment process contemplated within thescope of the present invention involves placing the referred FeedstockHMFO or Product HMFO into contact in batches or continually with a fixedor slurry bed subject to the action of ultrasonic energy. The bedcomprises a heterogeneous catalytic material, such as a catalyst from ahydrotreatment unit. The load input temperature ranges between 25° C.and 300° C., preferably at a temperature ranging between 30° C. and 260°C. The pressure of the system is not critical and may be adjusted insuch a way that prior to treatment it is equal to or lower than thepressure of the previous unit and after treatment the current is at thenormal pressure of this system. Spatial velocity ranges from between0.10 h⁻¹ and 10 h⁻¹, preferably within a range of between 0.2 h⁻¹ and 6h⁻¹.

An advantage of the ultrasonic treatment process is that it operates atrelatively low temperature and pressure preserving the desirableproperties (such a lubricity, energy density, and aromaticity) of theISO 8217 (2017) compliant HMFO.

In this description, items already described above as part of the coreprocess have retained the same numbering and designation for ease ofdescription. As show in FIG. 2, a UTU 3 can be utilized to pre-treat theFeedstock HMFO prior to mixing with the Activating Gas 4 as part of thecore process disclosed above. While simplistically represented in thisdrawing, the UTU 3 may be multiple parallel or in series UTU's howeverthe UTU may be as simple as a single reactor vessel in which the HMFO isexposed to Ultrasound energy in the presence of catalyst. While a singlea fixed bed, flow through/contact vessel may be used, it may beadvantageous and it is preferable to have multiple contact vessels inparallel with each other to allow for one unit to be active while asecond or third unit are being reloaded. Such an arrangement involvingmultiple parallel contact vessels with pipes/switching valves, etc. . .. is well within the abilities of one of skill in the art of refineryprocess design and operation.

An alternative illustrative embodiment is shown in FIG. 3 in which a UTU17 is utilized after the core sulfur removal process step, but prior tothe separation of the Product HMFO 24 from any Residual Gas 20 andBy-Product 22 (i.e. mostly C₁-C₄ hydrocarbons, and wild naptha). In sucha configuration the UTU effectively acts as a polishing unit to removesulfur containing complex molecules present in the HMFO not removedunder the conditions in the core process step. As with the pre-treatmentUTU described above, the conditions in this post-treatment UTU aremoderate. It is believed that because this step of the process will beconducted under very modest conditions (i.e. moderately elevatedtemperatures sufficient to make the HMFO liquid-like in this process)that will have minimal to no adverse impact upon the bulk physicalproperties of the product HMFO. In this way one may achieve a level ofdesulfurization reduction for a HMFO not achieved otherwise whileminimizing the cracking of hydrocarbons and maintaining the otherdesirable bulk properties of the HMFO.

Product HMFO The Product HFMO resulting from the disclosed illustrativeprocess is of merchantable quality for sale and use as a heavy marinefuel oil (also known as a residual marine fuel oil or heavy bunker fuel)and exhibits the bulk physical properties required for the Product HMFOto be an ISO compliant (i.e. ISO 8217 (2017)) residual marine fuel oil.The Product HMFO should exhibit the bulk properties of: a maximum ofkinematic viscosity at 50° C. (ISO 3104) between the range from 180mm²/s to 700 mm²/s; a maximum of density at 15° C. (ISO 3675) betweenthe range of 991.0 kg/m³ to 1010.0 kg/m³; a CCAI is in the range of 780to 870; a flash point (ISO 2719) no lower than 60° C.; a totalsediment-aged (ISO 10307-2) less than 0.10 mass %; and a carbonresidue-micro method (ISO 10370) less than 20.00 mass % and preferably amaximum aluminum plus silicon (ISO 10478) content less than 60 mg/kg.

The Product HMFO has a sulfur content (ISO 14596 or ISO 8754) less than0.5 wt % and preferably less than 0.1% wt. and complies with the IMOAnnex VI (revised) requirements for a low sulfur and preferably anultra-low sulfur HMFO. That is the sulfur content of the Product HMFOhas been reduced by about 80% or greater when compared to the FeedstockHMFO. Similarly, the vanadium content (ISO 14597) of the Product HeavyMarine Fuel Oil is less than 20% and more preferably less than 5% of themaximum vanadium content of the Feedstock Heavy Marine Fuel Oil. One ofskill in the art will appreciate that a substantial reduction in sulfurand vanadium content of the Feedstock HMFO indicates a process havingachieved a substantial reduction in the Environmental Contaminates fromthe Feedstock HMFO; of equal importance is this has been achieved whilemaintaining the desirable properties of an ISO 8217 (2017) compliantHMFO.

The Product HMFO not only complies with ISO 8217 (2017) (and ismerchantable as a residual marine fuel oil or bunker fuel), the ProductHMFO has a maximum sulfur content (ISO 14596 or ISO 8754) between therange of 0.05% wt. to 1.0% wt. preferably a sulfur content (ISO 14596 orISO 8754) between the range of 0.05% wt. ppm and 0.5% wt. and morepreferably a sulfur content (ISO 14596 or ISO 8754) between the range of0.1% wt. and 0.5% wt. The vanadium content of the Product HMFO is wellwithin the maximum vanadium content (ISO 14597) required for an ISO 8217(2017) residual marine fuel oil exhibiting a vanadium content lower than450 ppm mg/kg, preferably a vanadium content (ISO 14597) lower than 300mg/kg and more preferably a vanadium content (ISO 14597) less than 50mg/kg.

One knowledgeable in the art of marine fuel blending, bunker fuelformulations and the fuel logistical requirements for marine shippingfuels will readily appreciate that without further compositional changesor blending, the Product HMFO can be sold and used as a low sulfurMARPOL Annex VI compliant heavy (residual) marine fuel oil that is adirect substitute for the high sulfur heavy (residual) marine fuel oilor heavy bunker fuel currently in use. One illustrative embodiment is anISO 8217 (2017) compliant low sulfur heavy marine fuel oil comprising(and preferably consisting essentially of) a hydroprocessed ISO 8217(2017) compliant high sulfur heavy marine fuel oil, wherein the sulfurlevels of the hydroprocessed ISO 8217 (2017) compliant high sulfur heavymarine fuel oil is greater than 0.5% wt. and wherein the sulfur levelsof the ISO 8217 (2017) compliant low sulfur heavy marine fuel oil isless than 0.5% wt. Another illustrative embodiment is an ISO 8217 (2017)compliant ultra-low sulfur heavy marine fuel oil comprising (andpreferably consisting essentially of) a 100% hydroprocessed ISO 8217(2017) compliant high sulfur heavy marine fuel oil, wherein the sulfurlevels of the hydroprocessed ISO 8217 (2017) compliant high sulfur heavymarine fuel oil is greater than 0.5% wt. and wherein the sulfur levelsof the ISO 8217 (2017) compliant low sulfur heavy marine fuel oil isless than 0.1% wt.

Because of the present invention, multiple economic and logisticalbenefits to the bunkering and marine shipping industries can berealized. The benefits include minimal changes to the existing heavymarine fuel bunkering infrastructure (storage and transferring systems);minimal changes to shipboard systems are needed to comply with emissionsrequirements of MARPOL Annex VI (revised); no additional training orcertifications for crew members will be needed, amongst the realizablebenefits. Refiners will also realize multiple economic and logisticalbenefits, including: no need to alter or rebalance the refineryoperations, crude slates and product streams to meet a new market demandfor low sulfur or ultralow sulfur HMFO; no additional units are neededin the refinery with additional hydrogen or sulfur capacity because theillustrative process can be conducted as a stand-alone unit; refineryoperations can remain focused on those products that create the greatestvalue from the crude oil received (i.e. production of petrochemicals,gasoline and distillate (diesel); refiners can continue using theexisting slates of crude oils without having to switch to sweeter orlighter crudes to meet the environmental requirements for HMFO products.

Heavy Marine Fuel Composition One aspect of the present inventiveconcept is a fuel composition comprising, but preferably consistingessentially of, the Product HMFO resulting from the processes disclosed,and may optionally include Diluent Materials. The bulk properties of theProduct HMFO itself complies with ISO 8217 (2017) and meets the globalIMO Annex VI requirements for maximum sulfur content (ISO 14596 or ISO8754). If ultra low levels of sulfur are desired, the process of thepresent invention achieves this and one of skill in the art of marinefuel blending will appreciate that a low sulfur or ultra-low sulfurProduct HMFO can be utilized as a primary blending stock to form aglobal IMO Annex VI compliant low sulfur Heavy Marine Fuel Composition.Such a low sulfur Heavy Marine Fuel Composition will comprise (andpreferably consist essentially of): a) the Product HMFO and b) DiluentMaterials. In one embodiment, the majority of the volume of the HeavyMarine Fuel Composition is the Product HMFO with the balance ofmaterials being Diluent Materials. Preferably, the Heavy Marine FuelComposition is at least 75% by volume, preferably at least 80% byvolume, more preferably at least 90% by volume, and furthermorepreferably at least 95% by volume Product HMFO with the balance beingDiluent Materials.

Diluent Materials may be hydrocarbon or non-hydrocarbon based materialsmixed into or combined with or added to, or solid particle materialssuspended in, the Product HMFO. The Diluent Materials may intentionallyor unintentionally alter the composition of the Product HMFO but not sothe resulting mixture violates the ISO 8217 (2017) standards for theproperties of residual marine fuels or fails to have a sulfur contentlower than the global MARPOL standard of 0.5% wt. sulfur (ISO 14596 orISO 8754). Examples of Diluent Materials considered hydrocarbon basedmaterials include: Feedstock HMFO (i.e. high sulfur HMFO); distillatebased fuels such as road diesel, gas oil, MGO or MDO; cutter oil (whichis used in formulating residual marine fuel oils); renewable oils andfuels such as biodiesel, methanol, ethanol; synthetic hydrocarbons andoils based on gas to liquids technology such as Fischer-Tropsch derivedoils, synthetic oils such as those based on polyethylene, polypropylene,dimer, trimer and poly butylene; refinery residues or other hydrocarbonoils such as atmospheric residue, vacuum residue, fluid catalyticcracker (FCC) slurry oil, FCC cycle oil, pyrolysis gasoil, cracked lightgas oil (CLGO), cracked heavy gas oil (CHGO), light cycle oil (LCO),heavy cycle oil (HCO), thermally cracked residue, coker heavydistillate, bitumen, de-asphalted heavy oil, visbreaker residue, slopoils, asphaltinic oils; used or recycled motor oils; lube oil aromaticextracts and crude oils such as heavy crude oil, distressed crude oilsand similar materials that might otherwise be sent to a hydrocracker ordiverted into the blending pool for a prior art high sulfur heavy(residual) marine fuel oil. Examples of Diluent Materials considerednon-hydrocarbon based materials include: residual water (i.e. waterabsorbed from the humidity in the air or water that is miscible orsolubilized, sometimes as microemulsions, into the hydrocarbons of theProduct HMFO), fuel additives which can include, but are not limited todetergents, viscosity modifiers, pour point depressants, lubricitymodifiers, de-hazers (e.g. alkoxylated phenol formaldehyde polymers),antifoaming agents (e.g. polyether modified polysiloxanes); ignitionimprovers; anti rust agents (e.g. succinic acid ester derivatives);corrosion inhibitors; anti-wear additives, anti-oxidants (e.g. phenoliccompounds and derivatives), coating agents and surface modifiers, metaldeactivators, static dissipating agents, ionic and nonionic surfactants,stabilizers, cosmetic colorants and odorants and mixtures of these. Athird group of Diluent Materials may include suspended solids or fineparticulate materials that are present because of the handling, storageand transport of the Product HMFO or the Heavy Marine Fuel Composition,including but not limited to: carbon or hydrocarbon solids (e.g. coke,graphitic solids, or micro-agglomerated asphaltenes), iron rust andother oxidative corrosion solids, fine bulk metal particles, paint orsurface coating particles, plastic or polymeric or elastomer or rubberparticles (e.g. resulting from the degradation of gaskets, valve parts,etc. . . . ), catalyst fines, ceramic or mineral particles, sand, clay,and other earthen particles, bacteria and other biologically generatedsolids, and mixtures of these that may be present as suspendedparticles, but otherwise don't detract from the merchantable quality ofthe Heavy Marine Fuel Composition as an ISO 8217 (2017) compliant heavy(residual) marine fuel.

The blend of Product HMFO and Diluent Materials must be of merchantablequality as a low sulfur heavy (residual) marine fuel. That is the blendmust be suitable for the intended use as heavy marine bunker fuel andgenerally be fungible as a bunker fuel for ocean going ships. Preferablythe Heavy Marine Fuel Composition must retain the bulk physicalproperties required of an ISO 8217 (2017) compliant residual marine fueloil and a sulfur content lower than the global MARPOL standard of 0.5%wt. sulfur (ISO 14596 or ISO 8754) so that the material qualifies asMARPOL Annex VI Low Sulfur Heavy Marine Fuel Oil (LS-HMFO). The sulfurcontent of the Product HMFO can be lower than 0.5% wt. (i.e. below 0.1%wt sulfur (ISO 14596 or ISO 8754)) to qualify as a MARPOL Annex VIcompliant Ultra-Low Sulfur Heavy Marine Fuel Oil (ULS-HMFO) and a HeavyMarine Fuel Composition likewise can be formulated to qualify as aMARPOL Annex VI compliant ULS-HMFO suitable for use as marine bunkerfuel in the ECA zones. The Heavy Marine Fuel Composition of the presentinvention must meet those internationally accepted standards for thebulk properties of residual marine fuel oils including: a kinematicviscosity at 50° C. (ISO 3104) between the range from 180 mm²/s to 700mm²/s; a density at 15° C. (ISO 3675) between the range of 991.0 kg/m³to 1010.0 kg/m³; a CCAI is in the range of 780 to 870; a flash point(ISO 2719) no lower than 60° C.; a total sediment-aged (ISO 10307-2)less than 0.10 mass %; and a carbon residue-micro method (ISO 10370)less than 20.00 mass % and also preferably a maximum aluminum plussilicon (ISO 10478) content less than 60 mg/kg.

Production Plant Description: Turning now to a more detailedillustrative embodiment of a production plant implementing both the coreprocess and the ultrasonic desulfurization processes disclosed, FIGS. 4and 5 show a schematic for a production plant implementing the coreprocess described above combined with a pre-treatment ultrasoundtreatment unit (UTU) (FIG. 4, item 2) or a post-treatment UTU (FIG. 5,item 18), the combination which will reduce the environmentalcontaminates in a Feedstock HMFO to produce a Product HMFO that is ISO8217:2017 compliant and with the desired properties of a merchantableHMFO.

It will be appreciated by one of skill in the art that additionalalternative embodiments for the core process and the UTU may involvemultiple vessels and reactors even though only one of each is shown.Variations using multiple vessels/reactors are contemplated by thepresent invention but are not illustrated in greater detail forsimplicity sake.

The Reactor System (11) for the core process is described in greaterdetail below and using multiple vessels process has been described. Itwill be noted by one of skill in the art that in FIGS. 4 and 5, portionsof the production plant with similar function and operation have beenassigned the same reference number. This has been done for convenienceand succinctness only and differences between FIG. 4 and FIG. 5 are dulynoted and explained below.

In FIGS. 4 and 5, Feedstock HMFO (A) is fed from outside the batterylimits (OSBL) to the Oil Feed Surge Drum (1) that receives feed fromoutside the battery limits (OSBL) and provides surge volume adequate toensure smooth operation of the unit. Water entrained in the feed isremoved from the HMFO with the water being discharged a stream (1 c) fortreatment OSBL.

As shown in FIG. 4, the Feedstock HMFO (A) is withdrawn from the OilFeed Surge Drum (1) via line (1 b) by the Oil Feed Pump (3) and sent tothe UTU 2 as a pretreatment step. The pre-treated Feedstock HMFO ispressurized to a pressure required for the process. The pressurized HMFO(A′) then passes through line (3 a) to the Oil Feed/Product HeatExchanger (5) where the pressurized HMFO (A′) is partially heated by theProduct HMFO (B). The pressurized Feedstock HMFO (A′) passing throughline (5 a) is further heated against the effluent from the ReactorSystem (E) in the Reactor Feed/Effluent Heat Exchanger (7).

As shown in FIG. 5, the Feedstock HMFO (A) is withdrawn from the OilFeed Surge Drum (1) via line (1 b) by the Oil Feed Pump (3) and ispressurized to a pressure required for the core process. The pressurizedHMFO (A′) then passes through line (3 a) to the Oil Feed/Product HeatExchanger (5) where the pressurized HMFO (A′) is partially heated by theProduct HMFO (B). The pressurized Feedstock HMFO (A′) passing throughline (5 a) is further heated against the effluent from the ReactorSystem (E) in the Reactor Feed/Effluent Heat Exchanger (7).

In both FIG. 4 and FIG. 5, the heated and pressurized Feedstock HMFO(A″) in line (7 a) is then mixed with Activating Gas (C) provided vialine (23 c) at Mixing Point (X) to form a Feedstock Mixture (D). Themixing point (X) can be any well know gas/liquid mixing system orentrainment mechanism well known to one skilled in the art.

The Feedstock Mixture (D) passes through line (9 a) to the Reactor FeedFurnace (9) where the Feedstock Mixture (D) is heated to the specifiedprocess temperature. The Reactor Feed Furnace (9) may be a fired heaterfurnace or any other kind to type of heater as known to one of skill inthe art if it will raise the temperature of the Feedstock mixture to thedesired temperature for the process conditions.

The heated Feedstock Mixture (D′) exits the Reactor Feed Furnace (9) vialine 9 b and is fed into the Reactor System (11). The heated FeedstockMixture (D′) enters the Reactor System (11) where environmentalcontaminates, such a sulfur, nitrogen, and metals are preferentiallyremoved from the Feedstock HMFO component of the heated FeedstockMixture. The Reactor System contains a catalyst which preferentiallyremoves the sulfur compounds in the Feedstock HMFO component by reactingthem with hydrogen in the Activating Gas to form hydrogen sulfide. TheReactor System will also achieve demetalization, denitrogenation, and acertain amount of ring opening hydrogenation of the complex aromaticsand asphaltenes, however minimal hydrocracking of hydrocarbons shouldtake place. The process conditions of hydrogen partial pressure,reaction pressure, temperature and residence time as measured by liquidhourly velocity are optimized to achieve desired final product quality.A more detailed discussion of the Reactor System, the catalyst, theprocess conditions, and other aspects of the process are contained belowin the “Reactor System Description.”

The Reactor System Effluent (E) exits the Reactor System (11) via line(11 a) and exchanges heat against the pressurized and partially heatsthe Feedstock HMFO (A′) in the Reactor Feed/Effluent Exchanger (7). Thepartially cooled Reactor System Effluent (E′) then flows via line (11 c)to the Hot Separator (13).

The Hot Separator (13) separates the gaseous components of the ReactorSystem Effluent (F) which are directed to line (13 a) from the liquidcomponents of the Reactor System effluent (G) which are directed to line(13 b). The gaseous components of the Reactor System effluent in line(13 a) are cooled against air in the Hot Separator Vapor Air Cooler (15)and then flow via line (15 a) to the Cold Separator (17).

The Cold Separator (17) further separates any remaining gaseouscomponents from the liquid components in the cooled gaseous componentsof the Reactor System Effluent (F′). The gaseous components from theCold Separator (F″) are directed to line (17 a) and fed onto the AmineAbsorber (21). The Cold Separator (17) also separates any remaining ColdSeparator hydrocarbon liquids (H) in line (17 b) from any Cold Separatorcondensed liquid water (I). The Cold Separator condensed liquid water(I) is sent OSBL via line (17 c) for treatment.

In FIG. 4, the hydrocarbon liquid components of the Reactor Systemeffluent from the Hot Separator (G) in line (13 b) and the ColdSeparator hydrocarbon liquids (H) in line (17 b) are combined and arefed to the Oil Product Stripper System (19). The Oil Product StripperSystem (19) removes any residual hydrogen and hydrogen sulfide from theProduct HMFO (B) which is discharged in line (19 b) to storage OSBL. Itis also contemplated that a second draw (not shown) may be included towithdraw a distillate product, preferably a middle to heavy distillate.The vent stream (M) from the Oil Product Stripper in line (19 a) may besent to the fuel gas system or to the flare system that are OSBL.

In FIG. 5, the hydrocarbon liquid components of the Reactor Systemeffluent from the Hot Separator (G) in line (13 b) and the ColdSeparator hydrocarbon liquids (H) in line (17 b) are combined and arefed to the UTU (18) prior to being sent to the Oil Product StripperSystem (19). The Oil Product Stripper System (19) removes any residualhydrogen and hydrogen sulfide from the Product HMFO (B) which isdischarged in line (19 b) to storage OSBL. The vent stream (M) from theOil Product Stripper in line (19 a) may be sent to the fuel gas systemor to the flare system that are OSBL.

An alternative embodiment not shown in FIG. 5, but well within the skillof one in the art, would be to relocate the UTU (18) from the line priorto the Oil Product Stripper (19) to a location downstream of the OilProduct Stripper (19). Such a relocation of the UTU (18) to line (19 b)will allow for the ultrasound treatment of the final product HMFO priorto being sent to storage OSBL. This location is practicable because theUTU may induce desirable changes in the product HMFO without substantialproduction of light hydrocarbons (i.e. minimal cracking). The UTU mayalso impart an additional amount of stability to the Product HMFO.

The gaseous components from the Cold Separator (F″) in line (17 a)contain a mixture of hydrogen, hydrogen sulfide and light hydrocarbons(mostly methane and ethane). This vapor stream (17 a) feeds an AmineAbsorber (21) where it is contacted against Lean Amine (J) provided OSBLvia line (21 a) to the Amine Absorber (21) to remove hydrogen sulfidefrom the gases making up the Activating Gas recycle stream (C′). Richamine (K) which has absorbed hydrogen sulfide exits the bottom of theAmine Absorber (21) and is sent OSBL via line (21 b) for amineregeneration and sulfur recovery.

The Amine Absorber overhead vapor in line (21 c) is preferably recycledto the process as a Recycle Activating Gas (C′) via the RecycleCompressor (23) and line (23 a) where it is mixed with the MakeupActivating Gas (C″) provided OSBL by line (23 b). This mixture ofRecycle Activating Gas (C′) and Makeup Activating Gas (C″) to form theActivating Gas (C) utilized in the process via line (23 c) as notedabove. A Scrubbed Purge Gas stream (H) is taken from the Amine Absorberoverhead vapor line (21 c) and sent via line (21 d) to OSBL to preventthe buildup of light hydrocarbons or other non-condensables.

Reactor System Description: The core process Reactor System (11)illustrated in FIG. 4 and FIG. 5 comprises a single reactor vesselloaded with the process catalyst and sufficient controls, valves andsensors as one of skill in the art would readily appreciate.

Alternative Reactor Systems in which more than one reactor vessel may beutilized in parallel or in a cascading series can easily be substitutedfor the single reactor vessel Reactor System 11 shown. In such anembodiment, each reactor vessel is similarly loaded with processcatalyst and can be provided the heated Feed Mixture (D′) via a commonline. The effluent from each of the three reactors is recombined in lineand forms a combined Reactor Effluent (E) for further processing asdescribed above. The illustrated arrangement will allow the threereactors to carry out the process effectively multiplying the hydrauliccapacity of the overall Reactor System. Control valves and isolationvalves may also prevent feed from entering one reactor vessel but notanother reactor vessel. In this way one reactor can be by-passed andplaced off-line for maintenance and reloading of catalyst while theremaining reactors continues to receive heated Feedstock Mixture (D′).It will be appreciated by one of skill in the art this arrangement ofreactor vessels in parallel is not limited in number to three, butmultiple additional reactor vessels can be added. The only limitation tothe number of parallel reactor vessels is plot spacing and the abilityto provide heated Feedstock Mixture (D′) to each active reactor.

In another illustrative embodiment cascading reactor vessels are loadedwith process catalyst with the same or different activities towardmetals, sulfur or other environmental contaminates to be removed. Forexample, one reactor may be loaded with a highly active demetallizationcatalyst, a second subsequent or downstream reactor may be loaded with abalanced demetallization/desulfurizing catalyst, and reactor downstreamfrom the second reactor may be loaded with a highly activedesulfurization catalyst. This allows for greater control and balance inprocess conditions (temperature, pressure, space flow velocity, etc. . .. ) so it is tailored for each catalyst. In this way one can optimizethe parameters in each reactor depending upon the material being fed tothat specific reactor/catalyst combination and minimize thehydrocracking reactions. As with the prior illustrative embodiment,multiple cascading series of reactors can be utilized in parallel and inthis way the benefits of such an arrangement noted above (i.e. allow oneseries to be “online” while the other series is “off line” formaintenance or allow increased plant capacity).

The reactor(s) that form the Reactor System may be fixed bed, ebulliatedbed or slurry bed or a combination. As envisioned, fixed bed reactorsare preferred as these are easier to operate and maintain.

The reactor vessel in the Reactor System is loaded with one or moreprocess catalysts. The exact design of the process catalyst system is afunction of feedstock properties, product requirements and operatingconstraints and optimization of the process catalyst can be carried outby routine trial and error by one of ordinary skill in the art.

The process catalyst(s) comprise at least one metal selected from thegroup consisting of the metals each belonging to the groups 6, 8, 9 and10 of the Periodic Table, and more preferably a mixed transition metalcatalyst such as Ni—Mo, Co—Mo, Ni—W or Ni—Co—Mo are utilized. The metalis preferably supported on a porous inorganic oxide catalyst carrier.The porous inorganic oxide catalyst carrier is at least one carrierselected from the group consisting of alumina, alumina/boria carrier, acarrier containing metal-containing aluminosilicate, alumina/phosphoruscarrier, alumina/alkaline earth metal compound carrier, alumina/titaniacarrier and alumina/zirconia carrier. The preferred porous inorganicoxide catalyst carrier is alumina. The pore size and metal loadings onthe carrier may be systematically varied and tested with the desiredfeedstock and process conditions to optimize the properties of theProduct HMFO. Such activities are well known and routine to one of skillin the art. Catalyst in the fixed bed reactor(s) may be dense-loaded orsock-loaded.

The catalyst selection utilized within and for loading the ReactorSystem may be preferential to desulfurization by designing a catalystloading scheme that results in the Feedstock mixture first contacting acatalyst bed that with a catalyst preferential to demetallizationfollowed downstream by a bed of catalyst with mixed activity fordemetallization and desulfurization followed downstream by a catalystbed with high desulfurization activity. In effect the first bed withhigh demetallization activity acts as a guard bed for thedesulfurization bed.

The objective of the Reactor System is to treat the Feedstock HMFO atthe severity required to meet the Product HMFO specification.Demetallization, denitrogenation and hydrocarbon hydrogenation reactionsmay also occur to some extent when the process conditions are optimizedso performing the Reactor System achieves the required level ofdesulfurization. Hydrocracking is preferably minimized to reduce thevolume of hydrocarbons formed as by-product hydrocarbons to the process.The objective of the process is to selectively remove the environmentalcontaminates from Feedstock HMFO and minimize the formation ofunnecessary by-product hydrocarbons.

The process reactive conditions in each reactor vessel will depend uponthe feedstock, the catalyst utilized and the desired final properties ofthe Product HMFO desired. Variations in conditions are to be expected byone of ordinary skill in the art and these may be determined by pilotplant testing and systematic optimization of the process. With this inmind it has been found that the operating pressure, the indicatedoperating temperature, the ratio of the Activating Gas to FeedstockHMFO, the partial pressure of hydrogen in the Activating Gas and thespace velocity all are important parameters to consider. The operatingpressure of the Reactor System should be in the range of 250 psig and3000 psig, preferably between 1000 psig and 2500 psig and morepreferably between 1500 psig and 2200 psig. The indicated operatingtemperature of the Reactor System should be 500° F. to 900° F.,preferably between 650° F. and 850° F. and more preferably between 680°F. and 800° F. The ratio of the quantity of the Activating Gas to thequantity of Feedstock HMFO should be in the range of 250 scf gas/bbl ofFeedstock HMFO to 10,000 scf gas/bbl of Feedstock HMFO, preferablybetween 2000 scf gas/bbl of Feedstock HMFO to 5000 scf gas/bbl ofFeedstock HMFO and more preferably between 2500 scf gas/bbl of FeedstockHMFO to 4500 scf gas/bbl of Feedstock HMFO. The Activating Gas should beselected from mixtures of nitrogen, hydrogen, carbon dioxide, gaseouswater, and methane, so Activating Gas has an ideal gas partial pressureof hydrogen (p_(H2)) greater than 80% of the total pressure of theActivating Gas mixture (P) and preferably wherein the Activating Gas hasan ideal gas partial pressure of hydrogen (p_(H2)) greater than 95% ofthe total pressure of the Activating Gas mixture (P). The Activating Gasmay have a hydrogen mole fraction in the range between 80% of the totalmoles of Activating Gas mixture and more preferably wherein theActivating Gas has a hydrogen mole fraction between 80% and 99% of thetotal moles of Activating Gas mixture. The liquid hourly space velocitywithin the Reactor System should be between 0.05 oil/hour/m3 catalystand 1.0 oil/hour/m3 catalyst; preferably between 0.08 oil/hour/m3catalyst and 0.5 oil/hour/m3 catalyst and more preferably between 0.1oil/hour/m3 catalyst and 0.3 oil/hour/m3 catalyst to achieve deepdesulfurization with product sulfur levels below 0.1 ppmw.

The hydraulic capacity rate of the Reactor System should be between 100bbl of Feedstock HMFO/day and 100,000 bbl of Feedstock HMFO/day,preferably between 1000 bbl of Feedstock HMFO/day and 60,000 bbl ofFeedstock HMFO/day, more preferably between 5,000 bbl of FeedstockHMFO/day and 45,000 bbl of Feedstock HMFO/day, and even more preferablybetween 10,000 bbl of Feedstock HMFO/day and 30,000 bbl of FeedstockHMFO/day. The desired hydraulic capacity may be achieved in a singlereactor vessel Reactor System or in a multiple reactor vessel ReactorSystem.

These examples will provide one skilled in the art with a more specificillustrative embodiment for conducting the process disclosed and claimedherein:

Example 1

Overview:

The purpose of a pilot test run is to demonstrate that feedstock HMFOcan be processed through a reactor loaded with commercially availablecatalysts at specified conditions to remove environmental contaminates,specifically sulfur and other contaminants from the HMFO to produce aproduct HMFO that is MARPOL compliant, that is production of a LowSulfur Heavy Marine Fuel Oil (LS-HMFO) or Ultra-Low Sulfur Heavy MarineFuel Oil (USL-HMFO).

Pilot Unit Set Up:

The pilot unit will be set up with two 434 cm³ reactors arranged inseries to process the feedstock HMFO. The lead reactor will be loadedwith a blend of a commercially available hydro-demetaling (HDM) catalystand a commercially available hydro-transition (HDT) catalyst. One ofskill in the art will appreciate that the HDT catalyst layer may beformed and optimized using a mixture of HDM and HDS catalysts combinedwith an inert material to achieve the desired intermediate/transitionactivity levels. The second reactor will be loaded with a blend of thecommercially available hydro-transition (HDT) and a commerciallyavailable hydrodesulfurization (HDS). One can load the second reactorsimply with a commercially hydrodesulfurization (HDS) catalyst. One ofskill in the art will appreciate that the specific feed properties ofthe Feedstock HMFO may affect the proportion of HDM, HDT and HDScatalysts in the reactor system. A systematic process of testingdifferent combinations with the same feed will yield the optimizedcatalyst combination for any feedstock and reaction conditions. For thisexample, the first reactor will be loaded with ⅔ hydro-demetalingcatalyst and ⅓ hydro-transition catalyst. The second reactor will beloaded with all hydrodesulfurization catalyst. The catalysts in eachreactor will be mixed with glass beads (approximately 50% by volume) toimprove liquid distribution and better control reactor temperature. Forthis pilot test run, one should use these commercially availablecatalysts: HDM: Albemarle KFR 20 series or equivalent; HDT: AlbemarleKFR 30 series or equivalent; HDS: Albemarle KFR 50 or KFR 70 orequivalent. Once set up of the pilot unit is complete, the catalyst canbe activated by sulfiding the catalyst using dimethyldisulfide (DMDS) ina manner well known to one of skill in the art.

Pilot Unit Operation:

Upon completion of the activating step, the pilot unit will be ready toreceive the feedstock HMFO and Activating Gas feed. For the presentexample, the Activating Gas can be technical grade or better hydrogengas. The mixed Feedstock HMFO and Activating Gas will be provided to thepilot plant at rates and operating conditions as specified: Oil FeedRate: 108.5 ml/h (space velocity=0.25/h); Hydrogen/Oil Ratio: 570 Nm3/m3(3200 scf/bbl); Reactor Temperature: 372° C. (702° F.); Reactor OutletPressure: 13.8 MPa(g) (2000 psig).

One of skill in the art will know that the rates and conditions may besystematically adjusted and optimized depending upon feed properties toachieve the desired product requirements. The unit will be brought to asteady state for each condition and full samples taken so analyticaltests can be completed. Material balance for each condition should beclosed before moving to the next condition.

Expected impacts on the Feedstock HMFO properties are: Sulfur Content(wt %): Reduced by at least 80%; Metals Content (wt %): Reduced by atleast 80%; MCR/Asphaltene Content (wt %): Reduced by at least 30%;Nitrogen Content (wt %): Reduced by at least 20%; C1-Naphtha Yield (wt%): Not over 3.0% and preferably not over 1.0%.

Process conditions in the Pilot Unit can be systematically adjusted asper Table 1 to assess the impact of process conditions and optimize theperformance of the process for the specific catalyst and feedstock HMFOutilized.

TABLE 1 Optimization of Process Conditions HC Feed Rate (ml/h), Nm³H₂/m³ oil/ Temp Pressure Case [LHSV(/h)] scf H₂/bbl oil (° C./° F.)(MPa(g)/psig) Baseline 108.5 [0.25] 570/3200 372/702 13.8/2000 T1 108.5[0.25] 570/3200 362/684 13.8/2000 T2 108.5 [0.25] 570/3200 382/72013.8/2000 L1 130.2 [0.30] 570/3200 372/702 13.8/2000 L2  86.8 [0.20]570/3200 372/702 13.8/2000 H1 108.5 [0.25] 500/2810 372/702 13.8/2000 H2108.5 [0.25] 640/3590 372/702 13.8/2000 S1  65.1 [0.15] 620/3480 385/72515.2/2200

In this way, the conditions of the pilot unit can be optimized toachieve less than 0.5% wt. sulfur product HMFO and preferably a 0.1% wt.sulfur product HMFO. Conditions for producing ULS-HMFO (i.e. 0.1% wt.sulfur product HMFO) will be: Feedstock HMFO Feed Rate: 65.1 ml/h (spacevelocity=0.15/h); Hydrogen/Oil Ratio: 620 Nm³/m³ (3480 scf/bbl); ReactorTemperature: 385° C. (725° F.); Reactor Outlet Pressure: 15 MPa(g) (2200psig)

Table 2 summarizes the anticipated impacts on key properties of HMFO.

TABLE 2 Expected Impact of Process on Key Properties of HMFO PropertyMinimum Typical Maximum Sulfur Conversion/Removal 80% 90% 98% MetalsConversion/Removal 80% 90% 100%  MCR Reduction 30% 50% 70% AsphalteneReduction 30% 50% 70% Nitrogen Conversion 10% 30% 70% C1 through NaphthaYield 0.5%  1.0%  4.0%  Hydrogen Consumption (scf/bbl) 500 750 1500

Table 3 lists analytical tests to be carried out for thecharacterization of the Feedstock HMFO and Product HMFO. The analyticaltests include those required by ISO for the Feedstock HMFO and theproduct HMFO to qualify and trade in commerce as ISO compliant residualmarine fuels. The additional parameters are provided so that one skilledin the art can understand and appreciate the effectiveness of theinventive process.

TABLE 3 Analytical Tests and Testing Procedures Sulfur Content ISO 8754or ISO 14596 or ASTM D4294 Density @ 15° C. ISO 3675 or ISO 12185Kinematic Viscosity @ 50° C. ISO 3104 Pour Point, ° C. ISO 3016 FlashPoint, ° C. ISO 2719 CCAI ISO 8217, ANNEX B Ash Content ISO 6245 TotalSediment - Aged ISO 10307-2 Micro Carbon Residue, mass % ISO 10370 H2S,mg/kg IP 570 Acid Number ASTM D664 Water ISO 3733 Specific ContaminantsIP 501 or IP 470 (unless indicated otherwise) Vanadium or ISO 14597Sodium Aluminum or ISO 10478 Silicon or ISO 10478 Calcium or IP 500 Zincor IP 500 Phosphorous IP 500 Nickle Iron Distillation ASTM D7169 C:HRatio ASTM D3178 SARA Analysis ASTM D2007 Asphaltenes, wt % ASTM D6560Total Nitrogen ASTM D5762 Vent Gas Component Analysis FID GasChromatography or comparable

Table 4 contains the Feedstock HMFO analytical test results and theProduct HMFO analytical test results expected from the inventive processthat indicate the production of a LS HMFO. It will be noted by one ofskill in the art that under the conditions, the levels of hydrocarboncracking will be minimized to levels substantially lower than 10%, morepreferably less than 5% and even more preferably less than 1% of thetotal mass balance.

TABLE 4 Analytical Results Feedstock HMFO Product HMFO Sulfur Content,mass % 3.0   0.3 Density @ 15° C., kg/m³ 990 950 ⁽¹⁾ Kinematic Viscosity@ 380 100 ⁽¹⁾ 50° C., mm²/s Pour Point, ° C. 20 10  Flash Point, ° C.110 100 ⁽¹⁾ CCAI 850 820  Ash Content, mass % 0.1   0.0 Total Sediment -Aged, mass % 0.1   0.0 Micro Carbon Residue, mass % 13.0   6.5 H2S,mg/kg 0 0 Acid Number, mg KO/g 1   0.5 Water, vol % 0.5 0 SpecificContaminants, mg/kg Vanadium 180 20  Sodium 30 1 Aluminum 10 1 Silicon30 3 Calcium 15 1 Zinc 7 1 Phosphorous 2 0 Nickle 40 5 Iron 20 2Distillation, ° C./° F. IBP 160/320 120/248  5% wt 235/455 225/437 10%wt 290/554 270/518 30% wt 410/770 370/698 50% wt  540/1004 470/878 70%wt  650/1202  580/1076 90% wt  735/1355  660/1220 FBP  820/1508 730/1346 C:H Ratio (ASTM D3178) 1.2   1.3 SARA Analysis Saturates 1622  Aromatics 50 50  Resins 28 25  Asphaltenes 6 3 Asphaltenes, wt % 6.0  2.5 Total Nitrogen, mg/kg 4000 3000   Note: ⁽¹⁾ property will beadjusted to a higher value by post process removal of light material viadistillation or stripping from product HMFO.

The product HMFO produced by the inventive process will reach ULS HMFOlimits (i.e. 0.1% wt. sulfur product HMFO) by systematic variation ofthe process parameters, for example by a lower space velocity or byusing a Feedstock HMFO with a lower initial sulfur content.

Example 2: RMG-380 HMFO

Pilot Unit Set Up:

A pilot unit was set up as noted above in Example 1 with these changes:the first reactor was loaded with: as the first (upper) layerencountered by the feedstock 70% vol Albemarle KFR 20 serieshydro-demetaling catalyst and 30% vol Albemarle KFR 30 serieshydro-transition catalyst as the second (lower) layer. The secondreactor was loaded with 20% Albemarle KFR 30 series hydrotransitioncatalyst as the first (upper) layer and 80% vol hydrodesulfurizationcatalyst as the second (lower) layer. The catalyst was activated bysulfiding the catalyst with dimethyldisulfide (DMDS) in a manner wellknown to one of skill in the art.

Pilot Unit Operation:

Upon completion of the activating step, the pilot unit was ready toreceive the feedstock HMFO and Activating Gas feed. The Activating Gaswas technical grade or better hydrogen gas. The Feedstock HMFO was acommercially available and merchantable ISO 8217 (2017) compliant HMFO,except for a high sulfur content (2.9 wt %). The mixed Feedstock HMFOand Activating Gas was provided to the pilot plant at rates andconditions as specified in Table 5 below. The conditions were varied tooptimize the level of sulfur in the product HMFO material.

TABLE 5 Process Conditions Product HC Feed Nm³ H₂/ Temp Pressure HMFORate (ml/h), m³ oil/scf (° C./ (MPa(g)/ Sulfur Case [LHSV(/h)] H₂/bbloil ° F.) psig) % wt. Baseline 108.5 [0.25] 570/3200 371/700 13.8/20000.24 T1 108.5 [0.25] 570/3200 362/684 13.8/2000 0.53 T2 108.5 [0.25]570/3200 382/720 13.8/2000 0.15 L1 130.2 [0.30] 570/3200 372/70213.8/2000 0.53 S1  65.1 [0.15] 620/3480 385/725 15.2/2200 0.10 P1 108.5[0.25] 570/3200 371/700    /1700 0.56 T2/P1 108.5 [0.25] 570/3200382/720    /1700 0.46

Analytical data for a representative sample of the feedstock HMFO andrepresentative samples of product HMFO are below:

TABLE 6 Analytical Results - HMFO (RMG-380) Feedstock Product ProductSulfur Content, mass % 2.9 0.3 0.1 Density @ 15° C., kg/m³ 988 932 927Kinematic Viscosity @ 382 74 47 50° C., mm²/s Pour Point, ° C. −3 −12−30 Flash Point, ° C. 116 96 90 CCAI 850 812 814 Ash Content, mass %0.05 0.0 0.0 Total Sediment - Aged, 0.04 0.0 0.0 mass % Micro CarbonResidue, 11.5 3.3 4.1 mass % H2S, mg/kg 0.6 0 0 Acid Number, mg KO/g 0.30.1 >0.05 Water, vol % 0 0.0 0.0 Specific Contaminants, mg/kg Vanadium138 15 <1 Sodium 25 5 2 Aluminum 21 2 <1 Silicon 16 3 1 Calcium 6 2 <1Zinc 5 <1 <1 Phosphorous <1 2 1 Nickle 33 23 2 Iron 24 8 1 Distillation,° C./° F. IBP 178/352 168/334 161/322  5% wt 258/496 235/455 230/446 10%wt 298/569 270/518 264/507 30% wt 395/743 360/680 351/664 50% wt 517/962461/862 439/822 70% wt  633/1172  572/1062  552/1026 90% wt  >720/>1328 694/1281  679/1254 FBP  >720/>1328  >720/>1328  >720/>1328 C:H Ratio(ASTM D3178) 1.2 1.3 1.3 SARA Analysis Saturates 25.2 28.4 29.4Aromatics 50.2 61.0 62.7 Resins 18.6 6.0 5.8 Asphaltenes 6.0 4.6 2.1Asphaltenes, wt % 6.0 4.6 2.1 Total Nitrogen, mg/kg 3300 1700 1600

In Table 6, both feedstock HMFO and product HMFO exhibited observed bulkproperties consistent with ISO 8217 (2017) for a merchantable residualmarine fuel oil, except that the sulfur content of the product HMFO wasreduced as noted above when compared to the feedstock HMFO.

One of skill in the art will appreciate that the above product HMFOproduced by the inventive process has achieved not only an ISO 8217(2017) compliant LS HMFO (i.e. 0.5% wt. sulfur) but also an ISO 8217(2017) compliant ULS HMFO limits (i.e. 0.1% wt. sulfur) product HMFO.

Example 3: RMK-500 HMFO

The feedstock to the pilot reactor utilized in example 2 above waschanged to a commercially available and merchantable ISO 8217 (2017)RMK-500 compliant HMFO, except that it has high environmentalcontaminates (i.e. sulfur (3.3 wt %)). Other bulk characteristic of theRMK-500 feedstock high sulfur HMFO are provide below:

TABLE 7 Analytical Results- Feedstock HMFO (RMK-500) Sulfur Content,mass % 3.3 Density @ 15° C., kg/m³ 1006 Kinematic Viscosity @ 50° C.,mm²/s 500

The mixed Feedstock (RMK-500) HMFO and Activating Gas was provided tothe pilot plant at rates and conditions and the resulting sulfur levelsachieved in the table below

TABLE 8 Process Conditions HC Feed Rate Product (ml/h), Nm³ H₂/m³ oil/Temp Pressure (RMK-500) Case [LHSV(/h)] scf H₂/bbl oil (° C./° F.)(MPa(g)/psig) sulfur % wt. A 108.5 [0.25]  640/3600 377/710 13.8/20000.57 B 95.5 [0.22] 640/3600 390/735 13.8/2000 0.41 C 95.5 [0.22]640/3600 390/735 11.7/1700 0.44 D 95.5 [0.22] 640/3600 393/740 10.3/15000.61 E 95.5 [0.22] 640/3600 393/740 17.2/2500 0.37 F 95.5 [0.22]640/3600 393/740  8.3/1200 0.70 G 95.5 [0.22] 640/3600 416/780  8.3/1200

The resulting product (RMK-500) HMFO exhibited observed bulk propertiesconsistent with the feedstock (RMK-500) HMFO, except that the sulfurcontent was reduced as noted in the above table.

One of skill in the art will appreciate that the above product HMFOproduced by the inventive process has achieved a LS HMFO (i.e. 0.5% wt.sulfur) product HMFO having bulk characteristics of a ISO 8217 (2017)compliant RMK-500 residual fuel oil. It will also be appreciated thatthe process can be successfully carried out under non-hydrocrackingconditions (i.e. lower temperature and pressure) that substantiallyreduce the hydrocracking of the feedstock material. When conditions wereincreased to much higher pressure (Example E) a product with a lowersulfur content was achieved, however some observed that there was anincrease in light hydrocarbons and wild naphtha production.

This prophetic example will provide one skilled in the art with a morespecific illustrative embodiment for conducting the processes disclosed:

Prophetic Example of Ultrasound Treatment Unit Operation:

To exemplify the invention, experiments will be carried out usingreaction system disclosed in U.S. Pat. No. 4,168,295 or 6,897,628 andthe high powered ultrasonic transducers disclosed in U.S. Pat. No.7,275,440. A simple tube based flow through reactor such as thosedisclosed in US20090038932 or U.S. Pat. No. 9,339,785 if a catalystmaterial is to be present. In the present example a simple tube reactorwith a supported catalyst material such as that described in U.S. Pat.No. 9,339,785 is preferable. Associated pumps, heater, hydrogen gasmixers and feedstock HMFO material (either Feedstock HMFO or ProductHMFO from the prior process) will be connected to the tube reactor in aconventional manner. The feedstock should be heated so is has sufficientfluidity for pumping and flow through the reactor, preferably this willbe between about 150° C. and about 300° C. The ultrasound transduceroperating conditions used to process the ultrasound will be well knownto one of skill in the art. The acoustic power will be systematicallyvaried between about 200 W and 1000 W, however this will be dynamicallyoptimized depending upon the Feedstock and the desired degree ofdesulfurization desired. The reactor temperature must be carefullymonitored and the feedstock flow increased or decreased to control thereaction temperature in the range of about 200° C. and 400° C. The finalnominal temperature of the product between 230° C. and 300° C. Thereactionary system may have mechanical stirring within the reaction beditself in the form of static mixing elements or other inert packingmaterials. The catalysts chosen for this study were, NiMo or CoMo type,with metal sulfides as an active phase. With these catalysts the aim wasto conjugate in a synergic and localized form in the same active sites,the remaining catalytic activity during the active phase with its highcapacity to absorb ultrasounds. Hydrogen will be preferably presentduring the ultrasound treatment the reaction zone at a pressure rangingfrom one atmosphere to 400 psig.

It is expected that besides the desulfurization of the feedstock HMFO,the viscosity of the HMFO will be modified in such a manner to make itless viscous. In this way a highly viscous residual based high sulfurFeedstock HMFO otherwise ISO 8217 compliant, such as RMG 500 (KinematicViscosity of 500 at 50° C.) or RMG700 (Kinematic Viscosity of 500) at50° C. or even RMK500 or 700, may be more easily introduced in the coreprocess and processed with less formation of coke and other particlesthat may cause a rapid increase in reactor backpressure. As part of thepost Core Process treatment of the Product HMFO, the described processwill be carried out to condition the Product HMFO for easier transportand handling, increased compatibility and stability when blended withother marine fuel materials (i.e. MGO or MDO), and enhance the value ofthese materials as low sulfur HMFO.

Table 9 contains the expected analytical test results for (A) FeedstockHMFO; (B) the Core Process Product HMFO and (C) Overall Process(Core+post ultrasound treatment) from the inventive processes. Theseresults will indicate to one of skill in the art that the production ofa ULS HMFO can be achieved and will demonstrate the benefits ofultrasonic treatment of HMFO. It will be noted by one of skill in theart that under the conditions, the levels of hydrocarbon cracking willbe minimized to levels substantially lower than 10%, more preferablyless than 5% and even more preferably less than 1% of the total massbalance.

TABLE 9 Analytical Results A B C Sulfur Content, mass % 3.0 Less than0.5 Less than 0.1 Density @ 15° C., kg/m³ 990 950 ⁽¹⁾ 950 ⁽¹⁾ KinematicViscosity @ 380 100 ⁽¹⁾ <100 ⁽¹⁾  50° C., mm²/s Pour Point, ° C. 20 10 10  Flash Point, ° C. 110 100 ⁽¹⁾ 100 ⁽¹⁾ CCAI 850 820  820  AshContent, mass % 0.1   0.0   0.0 Total Sediment - Aged, 0.1   0.0   0.0mass % Micro Carbon Residue, 13.0   6.5   6.5 mass % H2S, mg/kg 0 0 0Acid Number, mg KO/g 1   0.5 Less than 0.5 Water, vol % 0.5 0 0 SpecificContaminants, mg/kg Vanadium 180 20  20  Sodium 30 1 1 Aluminum 10 1 1Silicon 30 3 3 Calcium 15 1 1 Zinc 7 1 1 Phosphorous 2 0 0 Nickle 40 5 5Iron 20 2 2 Distillation, ° C./° F. IBP 160/320 120/248 120/248  5% wt235/455 225/437 225/437 10% wt 290/554 270/518 270/518 30% wt 410/770370/698 370/698 50% wt  540/1004 470/878 470/878 70% wt  650/1202 580/1076  580/1076 90% wt  735/1355  660/1220  660/1220 FBP  820/1508 730/1346  730/1346 C:H Ratio (ASTM D3178) 1.2   1.3   1.3 SARA AnalysisSaturates 16 22  22  Aromatics 50 50  50  Resins 28 25  25  Asphaltenes6 3 3 Asphaltenes, wt % 6.0   2.5   2.5 Total Nitrogen, mg/kg 40003000   3000   Note: ⁽¹⁾ property may be adjusted to a higher value bypost process removal of light material via distillation or stripping.

It will be appreciated by those skilled in the art that changes could bemade to the illustrative embodiments described above without departingfrom the broad inventive concepts thereof. It is understood, therefore,that the inventive concepts disclosed are not limited to theillustrative embodiments or examples disclosed, but it is intended tocover modifications within the scope of the inventive concepts asdefined by the claims.

The invention claimed is:
 1. A process for reducing the environmentalcontaminants in a Feedstock Heavy Marine Fuel Oil, the processcomprising: contacting a Feedstock Heavy Marine Fuel Oil, wherein theFeedstock Heavy Marine Fuel Oil complies with ISO 8217 except for theenvironmental contaminates including a sulfur content (ISO 14596 or ISO8754) greater than 0.50 wt %, with ultrasound having a frequency in therange of about 10 kHz and about 100 megahertz and a sonic energy in therange of about 30 watts/cm² to about 300 watts/cm² and a temperatureranging between 30° C. and 260° C. to give an ultrasonic pre-treatedFeedstock Heavy Marine Fuel Oil: mixing a quantity of the ultrasonicpre-treated Feedstock Heavy Marine Fuel Oil with a quantity ofActivating Gas mixture to give a Feedstock Mixture: contacting theFeedstock Mixture with one or more supported transition metal catalystsunder reactive conditions to form a Process Mixture from said FeedstockMixture: receiving said Process Mixture and separating the Product HeavyMarine Fuel Oil liquid components from the Process Mixture and,discharging the Product Heavy Marine Fuel Oil.
 2. The process of claim1, wherein the step of contacting a Feedstock Heavy Marine Fuel Oil withultrasound takes place in the presence of water or supercritical waterin which the volume ratio of the Feedstock Heavy Marine Fuel Oil to thewater is from about 25:1 to about 1:5.
 3. The process of claim 2,wherein the step of contacting a Feedstock Heavy Marine Fuel Oil withultrasound further takes place in the presence of an oxidizing agentselected from the group consisting of hydrogen peroxide or a watersoluble organic peroxide.
 4. The process of claim 1, wherein the step ofcontacting a Feedstock Heavy Marine Fuel Oil with ultrasound takes placein the presence of one or more metal catalysts having atomic numbersselected from 21 through 29, 39 through 47, and 57 through
 79. 5. Theprocess of claim 1, wherein the step of contacting a Feedstock HeavyMarine Fuel Oil with ultrasound takes place in the presence of one ormore metal catalysts selected from the group consisting of: Fenton'sreagent; tungstic acid, phosphotungstic acid, and metal ion catalystsalts in which the metal is iron (II), iron (II), copper (I), copper(II), chromium (III), chromium (VI), molybdenum, tungsten, and vanadiumions.
 6. The process of claim 1, wherein the step of contacting aFeedstock Heavy Marine Fuel Oil with ultrasound takes place at a spacevelocity in the range from 0.10 h⁻¹ and 10 h⁻¹.
 7. The process of claim1, wherein the supported transition metal catalyst comprises: a porousinorganic oxide catalyst carrier and a transition metal catalyst,wherein the porous inorganic oxide catalyst carrier is at least onecarrier selected from the group consisting of alumina, alumina/boriacarrier, a carrier containing metal-containing aluminosilicate,alumina/phosphorus carrier, alumina/alkaline earth metal compoundcarrier, alumina/titania carrier and alumina/zirconia carrier, andwherein the transition metal catalyst is one or more metals selectedfrom the group consisting of group 6, 8, 9 and 10 of the Periodic Tableand wherein the Activating Gas mixture includes hydrogen gas and has anideal gas partial pressure of hydrogen (p_(H2)) greater than 80% of thetotal pressure of the gas mixture (P).
 8. The process of claim 7,wherein the contacting the Feedstock Mixture with one or more supportedtransition metal catalysts under reactive conditions is selected fromthe group consisting of: a ratio of the quantity of the Activating Gasto the quantity of Feedstock Heavy Marine Fuel Oil in the range of 250scf gas/bbl of Feedstock Heavy Marine Fuel Oil to 10,000 scf gas/bbl ofFeedstock Heavy Marine Fuel Oil; a total pressure between of 250 psigand 3000 psig; an indicated temperature between of 500° F. to 900° F.,and, wherein a liquid hourly space velocity is between 0.05 oil/hour/m³catalyst and 1.0 oil/hour/m³ catalyst.
 9. A process for reducing theenvironmental contaminants in a Feedstock Heavy Marine Fuel Oil, theprocess comprising: mixing a quantity of Feedstock Heavy Marine FuelOil, wherein the Feedstock Heavy Marine Fuel Oil complies with ISO 8217except for the environmental contaminates including a sulfur content(ISO 14596 or ISO 8754) greater than 0.50 wt %, with a quantity ofActivating Gas mixture to give a Feedstock Mixture; contacting theFeedstock Mixture with one or more catalysts under reactive conditionsto form a Process Mixture from said Feedstock Mixture; receiving saidProcess Mixture and separating the hydrocarbon liquid components of theProcess Mixture from the bulk gaseous components of the Process Mixture;receiving said hydrocarbon liquid components of the Process Mixture andcontacting said hydrocarbon liquid components of the Process Mixturewith ultrasound having a frequency in the range of about 10 kHz andabout 100 megahertz and a sonic energy in the range of about 30watts/cm² to about 300 watts/cm², and a temperature ranging between 30°C. and 260° C. to give an ultrasonic treated hydrocarbon liquidcomponent of the Process Mixture; subsequently separating Product HeavyMarine Fuel Oil liquid components from the ultrasonic treatedhydrocarbon liquid components of the Process Mixture to form the ProductHeavy Marine Fuel Oil; and, discharging the Product Heavy Marine FuelOil.
 10. The process of claim 9, wherein the step of contacting saidhydrocarbon liquid components of the Process Mixture with ultrasoundtakes place in the presence of water or supercritical water in which thevolume ratio of the hydrocarbon liquid components to the water is fromabout 25:1 to about 1:5.
 11. The process of claim 10, wherein the stepof contacting said hydrocarbon liquid components of the Process Mixturefurther takes place in the presence of an oxidizing agent selected fromthe group consisting of hydrogen peroxide or a water soluble organicperoxide.
 12. The process of claim 9, wherein the step of contactingsaid hydrocarbon liquid components of the Process Mixture withultrasound takes place in the presence of one or more metal catalystshaving atomic numbers selected from 21 through 29, 39 through 47, and 57through
 79. 13. The process of claim 9, wherein the step of contactingsaid hydrocarbon liquid components of the Process Mixture withultrasound takes place in the presence of one or more metal catalystsselected from the group consisting of: Fenton's reagent; tungstic acid,phosphotungstic acid, and metal ion catalyst salts in which the metal isiron (II), iron (III), copper (I), copper (II), chromium (II), chromium(VI), molybdenum, tungsten, and vanadium ions.
 14. The process of claim9, wherein the step of contacting said hydrocarbon liquid components ofthe Process Mixture with ultrasound takes place at a space velocity inthe range from 0.10 h⁻¹ and 10 h⁻¹.
 15. The process of claim 9, whereinthe supported transition metal catalyst comprises: a porous inorganicoxide catalyst carrier and a transition metal catalyst, wherein theporous inorganic oxide catalyst carrier is at least one carrier selectedfrom the group consisting of alumina, alumina/boria carrier, a carriercontaining metal-containing aluminosilicate, alumina/phosphorus carrier,alumina/alkaline earth metal compound carrier, alumina/titania carrierand alumina/zirconia carrier, and wherein the transition metal catalystis one or more metals selected from the group consisting of group 6, 8,9 and 10 of the Periodic Table and wherein the Activating Gas mixtureincludes hydrogen gas and has an ideal gas partial pressure of hydrogen(p_(H2)) greater than 80% of the total pressure of the gas mixture (P).16. The process of claim 15, wherein the contacting the FeedstockMixture with one or more supported transition metal catalysts underreactive conditions is selected from the group consisting of: a ratio ofthe quantity of the Activating Gas to the quantity of Feedstock HeavyMarine Fuel Oil in the range of 250 scf gas/bbl of Feedstock HeavyMarine Fuel Oil to 10,000 scf gas/bbl of Feedstock Heavy Marine FuelOil; a total pressure between of 250 psig and 3000 psig; an indicatedtemperature between of 500° F. to 900° F., and, wherein a liquid hourlyspace velocity is between 0.05 oil/hour/m³ catalyst and 1.0 oil/hour/m³catalyst.